Born in Paris, he acquired a great reputation as a lawyer, less by practice in the courts than in a consultative capacity. He strenuously opposed the "parlement Maupeou", devised by Chancellor Maupeou to replace the old judiciary bodies, refusing to plead before it. He was counsel for Louis René Edouard, cardinal de Rohan in the "affair of the diamond necklace". In 1785, he was elected to the Académie française. In 1789, he was returned as one of the deputies of the Third Estate in Paris to the States-General, where he supported revolutionary measures such as the union of the orders, the suspensive veto, the Civil Constitution of the Clergy, etc.
His excessive obesity, which in the National Constituent Assembly made him the butt of the Royalist jokes, prevented his practising at the bar for some years before 1789. When Louis XVI invited him to undertake his defence, he excused himself on this ground. In 1792, he published some constitutional observations in extenuation of the king's actions, which, in the circumstances of the time, would have taken some courage.
Target took no part in public affairs during the Reign of Terror. Under the Directory he was made a member of the Institut de France in 1796 and of the Court of Cassation in 1798. He lived to collaborate in the earlier stages of the new criminal code.